Factors Affecting the Actual Discharge Volume of Screw Air Compressors

1. Equipment RPM:

The discharge volume of the screw air compressor is proportional to its speed, which often varies with the voltage and frequency of the power grid. When the voltage or frequency decreases, the speed will drop, reducing the discharge volume of the screw air compressor.

2. Suction State:

Screw air compressors are volumetric compressors with a constant suction volume. When the suction temperature rises or the suction pipeline resistance is too high, causing the suction pressure to drop, the gas density decreases, which accordingly reduces the exhaust volume of the screw air compressor.

3. Gas Leak

The rotors do not touch each other or the housing during operation, maintaining a certain gap, which leads to gas leakage. When the pressure increases, the gas leaks through the gaps into the intake pipe and the slots that are currently drawing air, reducing the exhaust volume. To minimize leakage, sealing teeth are designed at the top of the driven rotor's teeth, and sealing grooves are cut at the root of the driving rotor's teeth. The ends are also machined with annular or strip-shaped sealing teeth. If these sealing lines wear out, the leakage will increase, so these factors should be considered during routine maintenance.

4. Cooling Effect:

Gases heat up during the compression process, and the temperature of the rotors and the casing also rises accordingly. Therefore, during the intake process, the gas expands due to being heated by the rotors and casing, thereby reducing the intake volume. Some screw air compressors use oil cooling in their rotors and water cooling for the casing, one of the purposes being to lower the temperature. When the cooling is ineffective, the temperature increases, and the exhaust volume of the screw air compressor decreases.